Gas-engine.



C. H. SAUVAN.

GAS ENGINE.

APPLICATION FILED JAN. 26, 1909.

1,913,619.. I Patented Jan.2,1912.

2 SHEBTS-SHEET l.

WITNESSES IIVVENTOR MW Ww A TTORIVE Y.

CHARLES H. SA'UVAN, 0F NEWARK, NEW JERSEY.

GAS-ENGINE.

To all whom it may concern Be it known that I, CHARLES H. SAUVAN, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain Improvements in Gas-Engines, of which the follow ing is a Specification.

This invention relates moreparticularly to the construction of the piston of a gas engine, and the objects of the invention are to secure a complete exhaust of the cylinde after an explosion and thus wholly clean out of said cylinder the gases resulting from such explosion, so that when the new charge enters it will not become mixed with a remainder ofsuch gases; to enable the cylinder to be charged without any possibility of drawing from the exhaust; to reduce the strain and shock upon the parts of the engine; to save and conserve the energy of the engine, and thus secure more efiective power, to provide a simple, durable construction, and to obtain other advantages and results as may be brought out in the following description.

Referring to the accompanying drawings, in which like numerals of reference indicate corresponding parts in. each of the several figures, Figure l is a longitudinalsectional view of the piston and cylinder of an engine of my improved construction, and Fig. 2 is a similar view showing the parts in different position.

The engine shown is of the iEour cycle type, and Fig. 1 shows the position of parts at the end ot the fourth cycle or beginning ofthe first, and Fig. 2 shows the position 01 the parts at the end of the second cycle or beginning of the third. Ih said drawings, 10 indicates a cylinder for the piston 11, said piston being connectedby a rod 12 to the crank 13 of the shaft 14. Said cylinder is at its sides jacketed or provided with chambers 15 in any suitable and ordinary manner, and at its end or head are fuel and exhaust chambers 16 and 17 respectively, which are wholly separate from each other. The fuel chamber-16 has a port 18 to which fuel gas may be supplied in any manner common to gas engines, and the chamber-17 has an outlet port 19 which may openinto the atmosphere, or otherwise as desired. The main exhaust of the engine is atits side, as shown at 20.

From each, of the chambers 16 and- 17 ports lead to the cylinder and are controlled Specification of Letters Patent,

the said ring 31.

Patented Jan. 23, 1912.

Application filed January 26, 1909. Serial No. 474,207.

mally hold said valves closed.

The piston 11 comprises an outer cylin drical section 21 closed at its inner end and provided adjacent thereto with the usual packing rings 22, and an inner section 23 adapted to slide in said outer section and being connected to the rod 12 by a wrist-pin 24 in any suitable and ordinary manner.

Said inner section has packing 25 ,to make it fit tight in the outer section, so that there is an inclosed air space 29 between the two sections. The size of this air space is shown as reduced by a filler'26 inserted therein and fastened to the section 23 by a bolt 27 obviously by difierent sizes of fillers the capacity of the chamber between the two piston sections can bemade whatever desired. A. helical spring 28 is arranged between the two piston sections inthe chamber 29, preferably surrounding the filler 26, as shown, and exerts its tension to hold said piston sections apart' The outside diameter of this spring 28 is substantially that of the air chamber and thus the spring is held substantially in axial coincidence with the piston sections. said spiral spring 28 for a considerable por- Furthermore, the filler 26 fits into tion of its length, and thus the said spring 7 lar plunger 33 on the inner piston section 23.

Cushionin means are thus provided, where by when t e inner section slides outward of the cylinder with respect to the outer section air is compressed in the annular chamber of spring could be employed for the same purpose. Preferably the inner edges of the flange 32 of the ring 31 have tapering slits 34 which allow a limited leakage and thus more gradual cushioning.

Upon the cylinder head is a bracket 35 in which is fulcrumed a lever 36 adapted at Obviously a cushioning,

one end as 37 to push the valve 171, and at its other end or arm being pivoted to a connecting rod 38 adapted to slide longitudinally in suitable bearings 39 at the side of .the cylinder. The end of this rod 38 is engaged by a cam 40 which isrotated by the shaft 14 through gears 41, 42 which reduce the motion .to cause said cam to rotate once for every two rotations of the crank shaft.

In operation, the parts being as shown in Fig. 1, the first cycle simply withdraws the entire piston 11 from the cylinder without materially-changing the relation of its outer and inner sections. This movement of the piston of course does not uncover the exhaust 20, but, the suction of it draws in a charge of fuel through the valve 16. During the second cycle, the inner section of the piston of course returns to the position shown in Fig. 1, but the outer section of the piston is compressing the charge of fuel, and compresses the spring 28 and air in the chamber 29 so that the relation of the two piston sections is as shown in Fig. 2. At this point the explosion occurs and the first momentary effect of it is to compress the spring 28 and air in the chamber29 still further and force the outer section of the piston closer to the inner section. This cushions the sudden and violent impact against the crank 13 and connecting parts of the engine, and at the same time stores up energy which is later exerted to accelerate the outward movement of the piston. The piston moves outward until it uncovers the exhaust port 20 when the cylinder chamber isvented, and the third cycle is completed. On the fourth cycle the piston is returned to the position shown in Fig. 1 by the combined movement of the inner section' the rod 38 and swinging the lever 36. When a new charge is afterward admitted, it thus enters a perfectly clean chamber.

The spring 28 between the two piston sections is preferably a light spring, and may even, under some circumstances, be dismounted on said seat and adapted to reduce the capacity of the cylinder, means detachably connecting said filling piece to its said seat, a single helical spring inclosing and fitting around said filler and supported thereby with its @onvolutions lying loosely between the filling piece and piston sections, whereby a single pressure distributed over the area of each piston end is secured and the spring held against lateral displacement with economy of space, and inlet and exhaust ports for said cylinder.

2. In a gas engine, the combination of a cylinder, an outer cylindrical piston section, an inner piston section in said outer section, means tending to hold said piston sections resiliently apart, a ring at-the outer end of the outer piston section projecting thereinto and forming therewith an inwardly-facing annular recess or chamber, said ring having slits in its inner edge, an annular plunger on the inner piston section adapted to enter said recess or chamber and fit the same, and inlet and exhaust means for said cylinder.

3. In a gas engine, the combination of a cyli nder, an outer cylindrical piston section,

an mner piston section in said outer section, a ring in the projecting end of the outer piston section forming therewith an annular recess or chamber and having tapering longitudinal slits in its edge, an annular plunger on the inner piston section adapted to' enter said recess or chamber, and inlet and exhaust means for said cylinder.

CHARLES H. SAUVAN.

In the presence of 'FRANCES E. BLoocET'r, FREDERICK GERMAINN, J r. 

